1. Field of the Invention
The invention concerns a refractometer with a measuring prism on whose measuring surface a sample to be tested can be mounted. The sample can be illuminated by a light beam emitted by a source of white light under a range of angles that includes the critical angle for total reflection. The refractometer also has a receiver for receiving the reflected light.
2. Description of the Related Art
Refractometers are used to measure the index of refraction of solid, liquid, or gaseous substances. In total reflectometers, such as the Abbe refractometer, the critical angle of the total reflection is determined with the use of a measuring prism of known index of refraction, which is brought into optical contact with the substance to be tested.
These refractometers operate with white light, because the effect of dispersion can be compensated by rotation of two direct-vision prisms in the observation telescope.